Paper calender pressure regulator



NOV. 7, 1933"I B A MALKIN A 1,934,233

vPAPER CALENDER PRESSURE REGULATOR Filed Jan. 9, 1931 3 Sheets-Sheet l FIG. E.

ATTORNEY Nov. 7 1933 l B. A. MALKIN 1,934,233

PAPER CALENDER PRESSURE REGULATOR -Fi1ed Jan. 9, 19:51 5 sheets-Sheet 2 Nov. 7, 1933. B, A. MALKIN PAPER CALENDER PRESSURE REGULATOR Filed Jan. 9, 1931V 3 Sheets-Sheet 3 R www mmm@ m m Patented Nov. 7, 1933 UNITED STATES PAPER CALENDER PRESSURE REGULATOR Bernard A. Malkin, Lachine, Quebec, Canada, assigner to Dominion Engineering Works Limited, Lachine, Quebec, Canada.

Application January 9, 193i, Serial No. 507,665 12 Claims. (Cl. 92.75)

This invention relates to-paper calendering machines and particularly to machines of the stack roll types f The object of the invention is to regulate the nip pressure ci the calender .to prevent injury to the paper or other material` being calendered.

We have found that the relatively large and heavy rolls used in modern calenders results in the development ci excessive nip pressures which tend to seriously impair the quality ci the paper or otner material subjected to the action c1 the calender.

Tlie present invention has been designed 'to alleviate this condition, in its preferred form, the invention consists in equipping the calender with fluid pressure cusluoring or weight relieying devices to exert upward pressure on 'the Journal bearings ci one or more selected rolls 2D of the calender to` regulate the nlp pressure at desired points and to prei/ent this pressure exceeding a predetermined maximum Value. The

same result may also Toe accomplished Toy the in'terposition of adjustable spring devices lietween the bearings of adjacent rolls.

Proceeding not? to a more detailed discussion of the invention, reference will be had to the accompanying drawings wherein Figure l is a, side view'oi a Vcalender equipped with nip pressure relieving devices constructed in accordance with 'this invention,

Figure 2 is an end View oi t e calender assembly shown in rligure l.

Figure 3 is a View "partly in elevation and partly in vertical section oi the cushioning or Weight relieving devices employed at one end .oi the calender. In tl'lis View tire calender frame is omitted only a few ci the calender rolls appear.

Figure i is a diagrammatic representing the extent to which the nin pressure is re lieved when the Weight relieving devices are operated to apply a gir/en lifting pressure to the rolls attached thereto.

Figure 5 is a fragmentary Vertical sectional View of a modified nip pressure relieving assembly.

Figure 6 is a fragmentary plan yiew ci the assembly shown in Figure 5.

Figure 7 is a sectional View taken along the line '7 7 of Figure 5.

Figure 8 is a fragmentary end elevation of a calender equipped with adjustable spring devices interposed between the roll bearings to a further means for regulating the "nip pressure.

Cil

i 'bottoni ci' 'tlie stack.

'1l designates the side columns of a calender frame equipped with the usual arrangement of calender rolls or cylinders appearing at 12. The calender is also shown to be equipped with the usual roll lifting mechanism comprising a pair of spaced standards i3 located at each endoi' the calender and having their upper ends connected by a cross head is 'which is raised and lowered through the agency of suitable :Fluid pressure applying means generally indic cated at l5. The standards i3 ci eacli pair are threaded to engage with the usual adjust= nuts .i6 supporting the rollengagng saddles lil.

Tire nin pressure regulating means comprising the present invention includes a pair oi. hollow vertical tubes le arranged tfi'tliin each oi the frame columns ll as shown to advantage in Figs. l and 2. Each tube 'i8 carries thereon a vertically spaced series oi split clamps or collars appearing, respectively, at 19u, leb and les. Tnese collarsare seated in suitable anuu= lar grooves formed in the tutes and appearing at its in Fig. 3 `ln the present' instance the collars les, carried oy ela-cli pair ci" tubes le, are shown in supporting engagement with the ends 2o ci' a roll hearing supporting meroicer 2l liar/ing its central portion attached to one ci the journal bearings oi the roll iront tide lt will ce apparent, lierrever, that the members 2l may be supported on the collars 19o and attached to tire searing of the lith. roll from the bottom oi the stack or may be supported on the collars luc and attacned to the hearing oi the 3rd roll from tine bottom of the stack.,

its shown more clearly in Fig. 3, the uriner end of each tufee le is connected to a piston 22 operating in, a cylinder 23, Fluid pressure is supplied, as hereinafter described, to tliese cylinders to act on the lower' faces ol' the pistons 22 in order to apply a lifting pressure to the movable journal 'bearings or" tl'ie roll which is attached to the tubes le by the members 2l. ln this Way a portion or" the Weight load imposed by the roll supported by the members 2l. is sustained 'oy tnr` duid admitted beneath the pistons 22 and, by controlling the effective pressure of this iiuid, the nip pressure developed between said roll and the next lower roll may te regulated as desired.

Suitable rods V255 are mounted to slide vertical- 1y in the tubes 18 and have their upper ends connected to pistons 27 operating in cylinders 28 located above the cylinders 23. The lower ends of these rods carry roll bearing supporting members 29 corresponding to the members 21 and attached to one of the journal bearings of the second bottom roll of the stack. Fluid pressure admitted beneath they pistons 27 servesto apply a lifting pressure to the bearings of all the rolls positioned above the bottom roll of the stack to regulate the final nip pressure developed between the two bottom rolls. The pistons 22 and 27 may be operated independently or simultaneously to provide a wide range of control with reference to regulating the nip pressure". Actuation of the pistons 27 serves to regulate the iinal nip pressure between the two lower -rolls of the stack, whereas independent actuation of the pistons 22 serves to regulate the final "nip pressure as well as the intermediate nip pressure developed between the roll attached t0 the tubes 18 and next lower roll of the stack. Simultaneous actuation of the pistons 22 and 27 provides for a further regulation of the nal nip pressure in addition to that obtained through the independent operation of said pistons. Any suitable method of supplying 'uid to the cylinders 23 and 28 may be employed. One method, which is cited merely by way oil example, is shown in Fig. 2, wherein it will be noted that the cylinders 23 are supplied with fiuid from a pump 3l through the medium of a combined accumulator and pressure reducing valve appearing at 32. The cylinders 28 are supplied with fluid in a similar manner from a suction piunp through a combined accumulator and reducing valve appearing at 33. The particular method of controlling the ow of duid to and from the cylinders is not believed to require extended discussion since any suitable method may be employed which will enable the desired lifting pressure to be applied to the bearings 'of selectedyrolls of the calender to regulate the nip pressure developed between the selected rolls and the lower rolls engaging therewith.

One example oi.' the extent to which the nip pressure of the calender may be regulated in accordance with this invention is diagrammatically illustrated in Fig. 4. In this figure, the

numbers at the left of the stack or rolls represent the nip pressures developed in the absence of the weight relieving device provided by this invention while the gures at the right of the stack indicate the reduced nip pressures" developed between certain of the rolls when the weight relieving device is applied as previously described. In this example, the weight relieving devices are operated to exert a lifting pressure of approximately 6435 lbs. on the calender rolls connected therewith.

In the modified assembly shown in Figures 5 to 7 inclusive, a fluid pressure weight relieving device of the diaphragm type is interposed between the movable journal bearings of adjacent rolls. Each device includes a pressure chamber 35, formed in the upper side of each roll bearing 36. Each pressure chamber is4 closed at the top by a flexible. diaphragm 37 having its marginal portion clamped between the side walls of the chamber and a clamping ring 38,- the latter being secured in place by the screws 39. A .plate 40. is fastened to the upperside of the diaphragm by a screw bolt 40a to provide a supporting surface for the underside of the adjacent upper bearing 36. The

clamping ring 38 is provided with an inwardly projecting ledge 38a which overhangs the marginal portion of lthe plate 40 to limit upward movement thereof. The regulation of the fluid pressure in each chamber 35 may be effected in any desired manner. In the present instance there is shown for this purpose a supply line 4l equipped with a pressure regulator 42, arelief valve 43, and a three way cock 44.

In the further modification shown in Figure 8 a pair of springs 46 are interposed between the bearings 10 of adjacent rolls, each spring being confined between adjustable cap members ,47 provided 'with Shanks 48 in screw threaded engagementwith the bearings. By adjustment of the cap members 47 the nip pressure of engaging rolls may be regulated as desired.

Having thus described my invention, what I clainf is:

1. A stack roll cale'nder equipped with .weight relieving devices exerting lifting pressure on the Abearings of one or more rolls of the stack to regulate the nip pressure of the calender.

2. A stack roll calender equipped with fluid pressure operated weight relieving devices associated with the bearings of one or more rolls of the stack to regulate the "nip pressure o1' the calender. v

3. A stack roll calender equipped with weight relieving devices associated with the bearings of one or more rolls of the stack to regulate the nip pressure of the calender and means for controlling the weight relieving action of said devices to prevent the maximum nip pressure exceeding a predetermined value.

4. A stack roll calender equipped with uid operated weight relieving devices associated with the bearings of one or more rolls of the stack to regulate the nip pressure between said roll or rolls and the engaging lower roll or rolls and means for controlling the weight relieving action of said devices.

5. A stack roll calender equipped with piston members operable to apply weight relieving pressure to the bearings of one or more rolls of the stack to regulate the nip pressure of the calender, cylinders containing said pistons and means for supplying fluid pressure to said cylinders.

6. A stack roll calender equipped with a weight relieving device connected to the bearings of the roll engaging the bottom roll of the stack and serving to regulate the "nip pressure between these two rolls, a second weight relieving device connected to the bearings of an intermediate roll located above the first mentioned roll to regulate the nip pressure between said intermediate roll and the next lower roll, and means for independently controlling the action of said devices.

7. A stack roll calender including a plurality of weight relieving mechanisms adapted to be respectively attached to the bearings of selected rolls of the stack to relieve the nip pressure developed between the 'selected rolls of the engaging lower rolls, one of said mechanisms inciuding houow tubular members having their ings of a further roll or the stack and pistons connected to the upper ends of said rods and operating in cylinders arranged above the rst mentioned cylinders, and means for supplying fluid pressure to,said cylinders to exert a lifting pressure on said pistons.

8. A calender equipped with weight relieving devices interposed between the journal bearings of adjacent rolls, said devices being controllable to regulate the nip pressure of the calender.

9. A calender equipped with weight relieving devices interposed between the journal bearings of adjacent rolls,` and independently controllable to regulate the nip pressure developed 'between selected rolls of the calender.

10. A calender equipped with uid pressure ,said bearings, and means for controlling pressure conditions with said chambers.

12. A calender equipped with adjustable nip pressure relieving spring devices interposed between tiie journal bearings of adjacent rolls.

BERNARD A. Ivi-Uilm.

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